I agree with a lot of what you said but would like to offer my own opinion on one or two points. I appreciate the variety of sources you used as it makes it very clear that your answer is based in a wide scope of research and not just personal opinion. I would also like to offer another possible angle, that of memory. Often times when attempting to keep things together in our heads something slips through the cracks, but when verbalized you're able to acknowledge each one individually and thus reduce the chance of losing one without realizing. In the context of this claim students that worked out loud were able to see the entirety of the problem while I believe it's possible that the other students may have missed a thing or two. That being said, you make many excellent points and I would agree with the fact that the article is most likely missing the point.